TY - CONF AU - Litorja, Maritoni AU - Johnson, Bettye AU - Fowler, J C2 - SPIE Conference on Optical Engineering and Applications | 2007 | DA - 2007-09-13 LA - en PB - SPIE Conference on Optical Engineering and Applications | 2007 | PY - 2007 TI - Area Measurements of Apertures for Exo-Atmospheric Solar Irradiance for JPL ER -